File: test/test.py

#!/usr/bin/env python

import os, sys
import pprint

def import_module(name, path):
    import imp
    try:
        mod_fp, mod_path, mod_desc  = imp.find_module(name, [path])
        mod = getattr( imp.load_module(name, mod_fp, mod_path, mod_desc), name )
    except ImportError as exc:
        mod = None
        sys.stderr.write("Error: failed to import module ({})".format(exc))
    finally:
        if mod_fp: mod_fp.close()
    return mod

# import the GrammarTemplate.py engine (as a) module, probably you will want to place this in another dir/package
GrammarTemplate = import_module('GrammarTemplate', os.path.join(os.path.dirname(__file__), '../src/python/'))
if not GrammarTemplate:
    print ('Could not load the GrammarTemplate Module')
    sys.exit(1)
else:    
    pass


def echo( s='' ):
    print (s)

echo('GrammarTemplate.VERSION = ' + GrammarTemplate.VERSION)
echo( )

tpl = "SELECT <column.select>[, <*column.select>]\nFROM <table.from>[, <*table.from>][\nWHERE (<?required.where>) AND (<?condition.where>)][\nWHERE <?required.where><?!condition.where>][\nWHERE <?!required.where><?condition.where>][\nGROUP BY <?group>[, <*group>]][\nHAVING (<?required.having>) AND (<?condition.having>)][\nHAVING <?required.having><?!condition.having>][\nHAVING <?!required.having><?condition.having>][\nORDER BY <?order>[, <*order>]][\nLIMIT <offset|0>, <?count>]"

sql = GrammarTemplate(tpl)

echo("input template:")
echo(tpl)

echo( )

echo("output:")
echo(sql.render({
    'column'      : { 'select' : [ 'field1', 'field2', 'field3', 'field4' ] },
    'table'       : { 'from' : [ 'tbl1', 'tbl2' ] },
    'condition'   : { 'where' : 'field1=1 AND field2=2', 'having' : 'field3=1 OR field4=2' },
    'count'       : 5
}))